Fork-tailed drongo-cuckoo

The fork-tailed drongo-cuckoo (Surniculus dicruroides) belongs to the family of cuckoos, roadrunners, koels and coucals, Cuculidae.
The fork-tailed drongo-cuckoo species are distributed in Indian subcontinent, southeast Asia and southern China. These cuckoo species are brood parasites, laying eggs in the nest of other birds and relying on the host to raise their young. These cuckoos are polytypic species.

Appearance, physical description and identification

The fork-tailed drongo-cuckoo (Surniculus dicruroides) is a small cuckoo with a forked tail, measuring 25 cm in length and weighing 30 to 50 grams. Both the sexes look alike.
The overall plumage of fork-tailed drongo-cuckoo is black with steel-blue gloss. The head and upper back are less glossy. In the nape there is often a concealed white patch at the base of the feathers.

The underparts are black. The long feathers on the leg are white. The undertail coverts have thin white bars. The underwing coverts are black. The bend of wing is black.

The inner pair of tail feathers aka rectrices (R1 and R2) are shorter than the next pair (R3). The R3 have outer web broad at tip. The R4 is curved, narrow and bent outward to give fork-tailed appearance. The outer tail feathers (R5) are short and have oblique white bars.

The juveniles are dull black and have fine white spots on head, wings and breast. The tail feathers have white tips with shallow fork. There is white patch on the nape. The nestlings have orange mouth lining.

The fork-tailed drongo-cuckoo bill is straight and black in color. The irises are dark brown. The skin around the eye is black. The feet are dark gray. Their call is a loud clear piping whistling sound "pip-pip-pip-pip-pip" in ascending notes.

Ecosystem and habitat

These fork-tailed drongo-cuckoo species have medium forest dependence. These species normally occur in altitudes from 0 to 2100 meters. The artificial ecosystems of these cuckoo species include rural gardens and plantations.

The natural ecosystems of these fork-tailed drongo-cuckoo species include tropical and subtropical dry shrublands, open forests, tropical and subtropical moist lowland forests, bamboo forests and tropical and subtropical mangrove vegetations.

Diet and feeding behavior

The diet of the fork-tailed drongo-cuckoo consists mainly of insects. Caterpillars and flying insects like dragon flies, bees, wasps, grasshoppers, locust, cicadas, beetles and moths are their primary food. Occasionally they feed on fruits and figs.

These cuckoos are mostly arboreal and glean insects from small branches and leaves in the canopy. They are also known to hawk insects.

Reproduction and breeding habits

These fork-tailed cuckoo species are brood parasites, laying eggs in the nest of other birds and relying on the host to raise their young. The breeding season coincides with breeding season of the local host species.

The breeding season of these fork-tailed drongo-cuckoo species in Nepal is during June. In India, the breeding season in general is from March to October. The laying season in Myanmar is from April to June.

The fork-tailed drongo-cuckoo lays a single egg in the host nest. The egg is white with fine purple splotches. The incubation period and fledging period are not known. The nestling cuckoo evicts the eggs and hatchlings of the host.

Migration and movement patterns

The fork-tailed drongo-cuckoo species are partially migrant birds.
The northern breeding cuckoo populations in central, north and northeast India, Nepal, Bangladesh, Bhutan, China, north Myanmar and north Vietnam migrate south from September onwards for wintering.

Some fork-tailed drongo-cuckoo populations in south India, Sri Lanka and China (Hainan) are resident.

Post breeding, the juvenile cuckoos may disperse and establish in new locations within the range. They may make local movements for feeding and breeding within their range.

Conservation and survival

The global population size of the fork-tailed drongo-cuckoo (Surniculus dicruroides) has not been quantified. The overall population trend of these species is reported to be decreasing.

Throughout its range this cuckoo species is reported to be locally common to rare. The generation length is 4.2 years. Its distribution size is about 9,710,000 sq.km.

Hunting and habitat loss and degradation are the main threats that may endanger the survival of these cuckoo species.

IUCN and CITES status

The fork-tailed drongo-cuckoo (Surniculus dicruroides) does not approach the thresholds for being Vulnerable, either under the range size criterion, or under the population trend criterion or under the population size criterion.

The IUCN (International Union for Conservation of Nature) has categorized and evaluated the cuckoo species and has listed it as of "Least Concern". The CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) status is ‘Not Evaluated’ for fork-tailed drongo-cuckoo (Surniculus dicruroides).